Category 2 (Gray Water): is defined as water that contains significant contamination and has the potential to cause discomfort or sickness if contacted or consumed by humans. Category 2 losses can contain potentially unsafe levels of microorganisms, or nutrients for microorganisms.

Category 3 water can pose substantial heath risks to the occupant. GTA Restoration recommends using only technicians who have been certified and trained in how to perform this type of mitigation. In a sewage loss, there can up be to 120 different viruses and bacteria in the water